Electric furnace



July 2l, 1925. 1,546,534

T. F. BAILY ELECTRIC FURNACE Original piled Aug. 28, 1923 Patented July21, 19215..

UNITED STATES 1,546,534 PATENT OFFICE.

THADDEUS F. -BAILY, F ALLIANCE, OHIO.

ELECTRIC FURNACE.

Continuation of application Serial No. 659,788, lednugust 28, 1923. Thisapplication med July 29, 192 Serial No. 728,880.

To all whom-t may concern.'

Beit kno-wn that I, THADDEUS Alliance, in the county of Stark and Stateof Ohio, have invented certain new and useful Improvements in ElectricFurnaces, of which the following is aspeciica'tion.

This invention relates to improvements in that type of furnaces in whichthe heating element consists in a refractory trough containing granularresistance material, through which an electric current is passed togenerate heat; and the improvement is a continuation of the commonsubject matter of my co-pending application Serial N o. 659,738, filedAugust 28, 1923.

The object of the improvement is to provide an arched or dome-likeresistor trough preferably supported at its base upon the side Wall ofthe furnace, and so shaped that the maximum intensity of current andheat generation will be produced around the inner and lower side-s ofthe trough for the purpose of utilizing the heat to raise thetemperature of the hearth while the roof of the furnaceis kept at aconsiderably lower temperature; a further object being to support theresistor trough at its base entirely upon the side wall ofthe furnace,the upper portion of the trough being arched away from the furnace wallto relieve the same from the high temperature generated in the trough.

The above and ancillary objects may be attained by an arched o-rdome-like `trough of refractory material, the peripheral base portionthereof being connected at its base to the furnace wall; granular,carbonaceous material being located in the trough and electrodesextending into the lower portion of the trough, in such position as toholdthe maximum intensity of current and heat generation around thelower and inner sides of the trough.

An embodiment of the invention thus set forthv in general terms isillustrated in the accompanying drawing, in which- Figure 1 is a'vertical, sectional view ofl the impro-ved furnace, taken on the line 1-1, Fig. 2;

Fig. 2, a horizontal sectional view ofthe furnace on the line 2 2, Fig.1; and

Fig. 3,1111v enlarged cross-sectional view of the trough and oneelectrode, showing diagrammatically the lines of conductivity.

F. BAILY, a citizen of the United States, residing atV Similar numeralsrefer to similar parts throughout the drawing.

The brick Work 1 of the furnace may be supported upon a metal plate 2,and is preferably formed of fire brick, having the lining of suitableheat resisting material forming the hearth 4, which may be concaved asshown in Fig. 1. p A charging opening 5 is provided in one side of thefurnace, above the hearth, and normally closed by a suitable door and apouring spout 6 communicates with the hearth. The brick work may besurrounded by ametal shell 8, provided at its upper edge with a sandtrough 9.

The heating element may be carried in a removable section, supportedupon the structure above described, and comprising the wall 10'of firebrick or similar refractory material, surrounded by the steel shell 12,preferably spaced therefrom, and having the depending lower edgearranged to be seated in the sand trough 9, forming a sand seal betweenthese two sections of the furnace. i

1 An annular rib 14, o-f carbon silicide or -similar refractorymaterial, may be built in the wall 1,0 and provided with the bevelededge 15, the arched outer Wall 16, of the trough, also of carbonsilicide, resting upon the rib 14. The lower portion of the wall 16 maybe located in proximity to the furnace wall, while the remainder of thewall is arched inward, away from the furnace wall.

The dome-like bottom wall 17 of the trough is also formed of carbonsilicide, or the like, and the outer edge 18 thereof may be beveled torest upon the beveled edge 15 of the rib 14.

VThe inner edge of the bottom wall 17 supports the arched inner wall 18of the trough which is also formed of carbon silicide or similarrefractory material. The contacting edges of the bottom and inner wallsof the trough may be beveled as shown lsistance body being designated bythe numeral 22. A

Embedded in the" resistance material,

preferably at diametrically opposite sides It is, of course, understoodthat theseV electrodes are located in an electric circuit, in a mannerwell known in this art, electric conductors 24 being connected to theterminals of the electrodes and leading to a suitable source of`electricity.

As shown in Figs. 1 and 3, the electrodes are preferably located in thelower part of the trough. Since'the inner wall 18 of e trough is archedthe lines of conductivity from one electrode to the other will naturallytake the shortest path shown by the lines in Fig. 3, these linesindicating the maximum intensity of current and heat generation.

As will be seen from an inspection of Fig. 3, the maximum intensity isthus held around the arched bottom wall 17 and inner wall 18 of thetrough, while the upper outer portion of the resistor material carriesless current and will run cooler, the relieving space between the outerwall 16 of the trough and the furnace -wall preventing damage to thefurnace wall.

With this construction of trough, the major portion of the heatgenerated in the resistance body will be directed upon the hearth, whilethe roof of the furnace will remain several hundred degrees cooler thanthe hearth. l

The termination of each electrode may be supported upon a bracket 25,connected to the shell of the removable section'of the furnace, thuspermitting this section to be moved as a unit after the electricconductors have been disconnected from the electrodes.

A metallic sand trough 26 ma be provided at the upper edge of the s ell12 of the removable section, and the brick roof 27, covered with themetal shell 28, may be provided with the depending flange 29 whichenters the sand trough 26, ,forming a sand seal between the removablesection and the roof.

From the above it-will be obvious that by Iconstructing the arched ordome-like resistor trough with the electrodes in the lower portion, theouter side of the trough is relieved, preventing :undue damage to thefurnace wall andthe maximum intensity of current and heat generation isheld around the'bottom and inner walls of the trough, producing thehighest temperature upon' the. I

nular resistance trough contacting with the furnace wall only at itsbase.

3. In an electric furnace, a resistance trough includlng an archedbottom wall,

and inwardly inclined side walls inclined away from the furnace wall.

4. In an electric furnace, an annular resistance trough including anarched'bottom wall and arched side walls.

5. In an electric furnace, an arched rc1` sistance trough containingresistance material, and electrodes located lin the lower portion ofsaid trough.

4 6. In an electric furnace, an annular resistance trough containing`resistance material and electrodes extending into the resistancematerial at opposite points in the trough, the bottoni and side walls ofthe trough being arched, whereby the lines of conductivity through theresistance material, between the electrodes, will produce the maximumintensity of current and heat generation around the inner and bottomwalls of the trough.

7. In an electric furnace, an arched resistance trough containingresistance material and spaced electrodes in the trough, said electrodesbeing so located with reference to the bottom of the trough that theshortest path of the current from electrode to electrode will producethe maximum intensity of current and heat generation upon the bottom ofthe trough.

8. In an electric furnace, an annular resistance trough including anarched bottom wall and arched side walls and containing resistancematerial, and electrodes located in the lower portion of said trough.

In testimony that I claim the above, I have hereunto subscribed my name.

TI-IADDEUS F. BAILY. I

